Field of Disclosure
This disclosure relates in general to the field of digital video and in particular to scalar quantization and rate control in a real time video codec.
Description of the Related Art
Raw digital video streams often consume immense digital storage space, and are prohibitively massive for transmission. To reduce storage space or transmission bandwidth requirements, a raw video stream is encoded to reduce its size. Typical video encoding involves the process of subtracting a reference frame from an original frame of video to obtain a residual frame containing less information than the original frame. Residual frames are then further processed to obtain a compressed digital video stream for transmission or storage. A typical video decoder receives the compressed digital video stream and decompresses the compressed digital video into the original video stream or a downgraded version of the digital video stream.
In the field of video coding, proper quantization parameter selection is an important consideration in encoding video frames in a video stream. Improved quantization parameter construction can improve the quality of the video and/or reduce the bandwidth used to transmit video of a given quality. A selected quantization parameter is typically maintained throughout the video coding process regardless of whether a new coding mode is considered, the signal model is changed, or a new distortion metric is introduced. This may introduce inefficiencies in rate-distortion performance.